Eye color in humans varies widely between ethnic groups and between individuals. Perceived eye color of a normal human is dependent on the presence of several colored pigments in the iris which are coded for by different genes.
Iris color plays and has played a significant social function as an attribute of beauty. In recent years, alteration of some types of iris color has become possible through the use of colored contact lenses. Such colored contact lenses can have a prescriptive optical power, or can be optically neutral such that the lenses serves a cosmetic function only.
There are several disadvantages associated with the use of colored contact lenses for cosmetic purposes. First, the lenses have the same potential complications of use as contact lenses with prescriptive optical powers, including allergic reactions to the lens material and infections from improper handling. Further, contact lenses cannot be tolerated by some potential users due to the discomfort. Additionally, colored contact lenses require a degree of dexterity to insert and remove that is not possessed by all potential users. Further, permanent changes in iris color cannot be achieved through the use of colored contact lenses.
Another method for altering iris color involves the use of colored lens implanted anterior to the iris. Such implants require an invasive procedure to place the lens in position. Because of the potential complication of an invasive procedure and of leaving a foreign body within the eye, the implantation of color lenses has not become a widely adopted procedure.
Therefore, there remains a need for a method to alter iris pigmentation in a human which does not require colored contact lenses or implanted lenses. Additionally, there remains a need for a method to alter iris pigmentation in a human which can permanently alter iris color.